hi zyzfer. i did that two months ago. i too had high anxiety, but a map. KNTO gives out english maps, with korean on it as well. but if you don't need that, anyway, it's step by step. i got my bike from a guy in itaewon and headed from there over one of the bridges nearby, and continued south. when i got to the express bus terminal, near kangnam, i kind of remembered how the bus headed south, but i asked one of the old 'guard' guys around the bus terminal how to get to cheonan. and headed that way. but it wasn't as simple as that, since there were satellite cities to hop through. i can't recall the names of those 'still in seoul' satellite cities, but gas station guys helped me out alot, pointing to the secondary highways which connected them. missed the secondary between the last satellite city and suwon, blundering onto the expressway, which is illegal, and the toll at suwon was up and spanky but i just blurted out a lot of energetic english about being told the wrong turn, and got off the expressway at suwon. at a gas station there the pump guy pointed out the number one, which leads straight south through pyongtaek and to cheonan. it's a secondary, a 1 with a green oval around it on the sign. that highway, like all secondaries, is legal, and every expressway in korea has a secondary paralleling it, and they're all on the map. that number one secondary is two lanes one way, two lanes the other, and busy with big, black soot coughing trucks on the right lane, where bikes are 'supposed' to be, for 'safety'. i got a big clunk of soot in my eye and had to stop, even though i had a viser, so clear goggles for daylight driving are best. i got some 'professional' biker goggles a couple of days ago, like the eye holes are super clear, but some kind of plastic, 'windshield', and padded with 'leather'. big, giant-googly things with super visibility, like divers have a big mask, except they're goggles. but i got them in a little town called chungu. if you go to 1stopkorea.com there's a blog by a guy which includes the biking shop area in seoul, for later, but i guess you'll just want to get it south asap and get familiar with it. anyway, goggles. like i said that right hand lane is barrelling with big trucks so be careful. have a map and rely on the gas station guys, pointing out you're on a bike and don't want the expressways. and take it to a bike shop near where you get it so it can be checked out to avoid any surprises, the brakes for example. my bike had been sitting for awhile and there wasn't any gas in it, and the seller 'didn't know much about it' since it was his roomate's who left and he just wanted to sell it for him, and forward the money to him in japan. but it was a kick getting it out, just straight south once hopped through of the satellites. no licence plate yet, either, but the cameras all along the number one and the cops in booths didn't click or care. easy does it, in daylight of course. don't 'oblige' the heavy trucks by staying too far off to the right, especially not where it's curby and lippy, it's asking for the two wheels to drop sideways and tip the bike into a wobble. and sunglasses will just let the soot in. stop and take a break now and again. happy trails!
re; licencing. get the old plates from the previous owner when you buy it, promising to turn them in at the cheonan licencing office. otherwise you'll have to wait for him to turn them in to a seoul licencing office, then the cheonan office will have to confirm they've been turned in. it's easier just to get the plates in hand, and turn them in at your local office, and faster. the insurance was about 80,000. the plate place in cheonan is kind of hard to find, it's a private little shop, looking just like a car wash place/garage. my boss drove me there, but i can get there by looking again. altogether it was about a hundred thousand.

Hey Captain, That was a great post , very encouraging, I'm hoping to buy a bike this weekend...I'd love to take it for a ride country ride, does anyone else have a tale to tell or some advice about mbike touring here?

hey redrob. i drove a bike down south of korea for a year, six months in taiwan, and two months here again. bikes were 125,150, now 500(vulcan).
compared to taiwan, there are just a trickle of people on bikes. with a lot of cars. the things to watch out for are the crossroads when you're driving the secondary highways. a fair amount have a blinking yellow light so everyone takes their turn, but it's like the 'budding in' that goes on in shop queues. but watch out for car drivers who seem to be annoyed with bikes, and pushing their weight around. and getting onto the highway. and doing a 'u-e' on the highway, not getting carried away with your maneuverability; those cars are coming on fast.
also, pedestrians. they'll see a bike coming and just walk across the highway, when they would NOT do this if a car was coming. they know that you will dump whereas if it was a car they'd just get hit, so you both would lose. so they figure you'll reduce speed and give them the space to cross. a country person carrying a parcel on their head, or some dog leaping onto the road.
cars have a nose-probing forward insistent way of wanting to enter the highway stream, and they WILL slowly crawl onto the highway right in front of you, knowing you will dump if you don't give them leeway. so you've got to reduce speed and follow, or pass. there's some non-recognition of your right to be on the highway here, and it's dangerous. some side-entries are hardly visible, with a ramp they're going up, so they'll 'pop up' out of 'nowhere' and be bobbing there apparently gleefully spooking the shite out of you.
some drivers, as i'm implying, seem to get a gas out of 'hazing' bike riders, like the road is a 'game'. if the traffic is bumper to bumper, like on the east coast summer beach-going season, you can pass the grid-locked crawling auto-goers stuck in a row, whizzing by merrily on the shoulder. some drivers will have plonked themselves over to the shoulder 'peering' around the column as if impatient, so they'll be in your way. some will pretend to quickly veer to the shoulder right in front of you, just to give you a shot of adrenaline for a jest. and there are opening doors to look out for when it's stopped. can't be going too fast here.
if you hit anybody or any thing, you're extremely liable. also dumped.
it's said if you're a bike driver you're a better car driver. gearing down and skid/seize-free braking takes more space. you have to be looking out for problems given less stability.
and the shoulders, wobbly and uncertain, especially if you've allowed yourself to be forced onto it by someone bearing up behind. there are some bali bali speedsters on the road who, once having passed you, proceed to amaze one with their rockstar recklessness. if these guys are behind, hang closer to the yellow line, not off to the shoulder.